Efficient geocasting to multiple regions in large-scale wireless sensor networks

Recently, large sensor networks with several thousands of nodes are being deployed over large geographic areas in the context of smart city projects. In these settings, there is often a need to send a message to all sensors contained in one of multiple geographic regions, for example, to query for a free parking spot in several streets. We present Recursive Multi-region Geocasting (RMG), a novel multi-region geocast routing protocol which addresses the problem of delivering data from a source to multiple remote geocast regions in large-scale wireless sensor networks. The key idea is to treat a remote group of geocast regions as a point destination and forward data packets along a straight line towards the group, until a division point at which the group is divided, and the packet is forwarded towards the sub-groups in the same fashion. RMG is lightweight as no state has to be maintained at the nodes and the computations are simple. Simulation shows that our protocol achieves lower path length overhead and network relay load while incurring less computation overhead when compared to state-of-the-art protocols.